设计模式（代理模式）

public interface Func {
    public void doAction();
}

public class FuncImpl implements Func {

    @Override
    public void doAction() {
        System.out.println("FuncImpl");
    }
}

public class ProxyFuncImpl implements Func {
    
    private Func func;
    
    ProxyFuncImpl(){
        func = new FuncImpl();
    }
    
    @Override
    public void doAction() {
        System.out.println("ProxyFuncImpl");
        func.doAction();
    }
}

public class App {

    public static void main(String[] args) {
        ProxyFuncImpl proxy = new ProxyFuncImpl();
        proxy.doAction();
    }
}

ProxyFuncImpl
FuncImpl